Aug 16, 2011—A number of manufacturers—especially those in the aerospace, automotive, sporting-goods and wind-energy industries—make products that contain composite materials consisting of epoxy or other polymer impregnated with carbon, glass, Kevlar or other types of fibers. Some of these manufacturers purchase premade composite material, in pre-impregnated form (prepreg). Prepreg is a temperature-sensitive material, and companies that manufacture and sell prepreg must store the composite materials at 0 degrees Celsius (32 degrees Fahrenheit) or colder to prolong their shelf life. Nonetheless, prepreg providers must warm the material slightly before they can cut off pieces requested by their customers. Often prepreg can sustain only a limited amount of "out time"—that is, time spent outside cold storage. A prepreg product's shelf life is reduced anytime it is taken out of the cooling environment. Material may have a total shelf life of 64 hours outside of the cooler, and cumulative out-time has to be calculated each time the product is removed.

DeltaTrak manufactures and sells portable test instruments and software that monitor and record environmental conditions such as temperature. When, in August of 2010, an aerospace-materials manufacturer, which has asked to be unnamed, came to DeltaTrak seeking a technology solution, its managers were hoping for technology that would track temperatures, such as a data logger or RFID, recalls Steve Russell, DeltaTrak's North American sales director. The aerospace product company had been using paper and pen to manage out-time tracking, a process that was labor intensive and prone to error if someone failed to record a time, wrote it incorrectly, or misplaced the paper.

DeltaTrak proposed a system that provided an automated solution that would not only record the amount of time each roll spends outside a freezer and how warm it got during that time, but send that data and alerts in real time to the relevant parties when the maximum limit for the product's exposure to temperatures warmer than 0 degrees Celsius was approaching.

DeltaTrak designed a solution that uses ZigBee-based RFID loggers, called FlashLink RF, six months ago. The initial deployment consists of approximately a dozen RFID loggers, with each tag placed inside a plastic sleeve that was adhered to the composite roll. The aerospace-materials manufacturer installed five DeltaTrak readers, known as repeaters, which receive 2.4 GHz signals transmitted by tags up to 25 meters away. The repeaters in turn form a mesh network, transmitting data via the ZigBee protocol to each other and to a gateway, which is another repeater device that receives the data and forwards it to the software residing, in this case, on a stand-alone laptop computer (the system software can reside on the user's back-end system or on a hosted Web-based server).